Dilute juice beverage products having cloudy or opaque appearance are well known in the art. The cloudy or opaque appearance of these dilute juice products is typically achieved by incorporating a beverage emulsion. Beverage emulsions can be either flavor emulsions (i.e., provide the beverage with flavor and cloudiness) or cloud emulsions (i.e., provide primarily cloudiness). Both types of beverage emulsions comprise an oil phase that is dispersed in a continuous water phase, i.e., they are "oil-in-water" emulsions. This oil phase is typically uniformly dispersed in the continuous water phase in the form of fine droplets that give the beverage its cloudy or opaque appearance.
Beverage emulsions are thermodynamically unstable systems that have a tendency to revert to their original state of two immiscible liquids (i.e., a two phase system). Since the oil is the dispersed phase, it exists as droplets that tend to separate, or "flocculate" by aggregating to form clumps. In the absence of weighting agents, the oil phase, being lighter than the water phase, can separate and rise to the top of the beverage container. This phenomenon is usually referred to as "creaming" and can manifest itself as an unsightly ring inside the neck of the bottle (a condition commonly referred to as "ringing") or as powdery "floc" on the shoulder of the bottle. Conversely, the oil phase can become attached to colloidal particles heavier than the water phase, in which case the oil phase will settle to the bottom of the container. This condition is usually referred to as "sedimentation" because the cloud appears as sediment on the bottom of the bottle.
To enhance the stability of these flavor/cloud emulsions, a thickener or blend of thickeners can be added to the dilute juice beverage. These include propylene glycol alginate, xanthan gum, pectin, starch, modified starch, gellan gum, and carboxymethylcellulose. See U.S. Pat. No. 5,376,396 (Clark), issued Dec. 27, 1994 (beverage stabilizing systems formed from a blend of gellan gum and carboxymethylcellulose that preferably includes propylene glycol alginate); U.S. Pat. No. 4,163,807 (Jackman), issued Aug. 7, 1979 (citrus fruit product containing fruit pulp that consists of citrus fruit juice or a fruit drink containing citrus fruit juice and a combination of gums consisting essentially of xanthan gum and sodium carboxymethyl cellulose). These thickeners essentially stabilize the flavor/cloud emulsion by increasing the relative viscosity of the dilute juice beverage. However, while stabilizing the flavor/cloud emulsion, these thickeners can also undesirably affect the beverage flavor and feel, especially if relatively large quantities of these thickeners are required. In this regard, xanthan gum is preferred because it imparts a relatively high viscosity at near-zero shear, which is typical during beverage storage, but shear thins dramatically to provide an appropriate thickness character when a beverage is consumed. Unfortunately, when included in the dilute juice beverage at higher levels, some thickeners, especially xanthan gum, can potentially destabilize the flavor/cloud emulsion.
The ability to stabilize flavor/cloud emulsions in dilute juice products can be further complicated by other beverage components typically present in the product. One such component that is desirably present in dilute juice beverages that are intended to be stored without refrigeration (e.g., at ambient temperatures) is an antimicrobial preservative. Dilute juice beverages, when exposed to food spoilage microorganisms, can provide a hospitable environment for rapid microbial growth. Such exposure can, and infrequently does, result from accidental inoculation of the dilute juice beverage during manufacturing or packaging. Food spoilage microorganisms can then rapidly proliferate by feeding on nutrients provided by the juice component of the dilute juice beverage.
Preservatives, such as sorbates, benzoates, organic acids, and combinations thereof have been used in dilute juice beverages to provide some degree of microbial inhibition. At levels effective to inhibit microbial growth, some of these preservatives can contribute off-flavors to dilute juice beverages. Accordingly, it has been recently suggested to use certain food grade polyphosphates (especially sodium hexametaphosphate) to enhance the potency of these preservatives at lower levels in dilute juice beverages. See U.S. Pat. No. 5,431,940 (Calderas), issued Jul. 11, 1995, which discloses the use of antimicrobial polyphosphates, such as sodium hexametaphosphate, with sorbate preservatives, such as potassium sorbate, in dilute juice beverages having relatively low water hardness.
However, it has been found that the presence of polyphosphates, especially sodium hexametaphosphate, in combination with xanthan gum, can have a destabilizing effect on flavor/cloud emulsions used in dilute juice beverages. While not being bound by theory, it is believed that polymeric materials, including sodium hexametaphosphate and xanthan gum, exist in a well-hydrated colloid-like state (i.e., each polymer is a separate phase) when mixed with sufficient water. Depending on the concentration of the polymeric material and its compatibility with other components in the beverage, each of these colloidal particles has its own unique tendency to phase separate and aggregate into clumps that exclude the droplets of the oil phase from part of the aqueous continuous phase. As the oil droplets are crowded into the remaining available space, the rate at which they, in turn, aggregate and begin to flocculate increases rapidly, causing ring and floc to occur much sooner than would otherwise be the case.
Accordingly, it would be desirable to be able to formulate dilute juice beverages that: (1) have stable flavor/cloud emulsions; (2) can be stored at ambient temperatures through the use of preservative systems that contain polyphosphates, especially sodium hexametaphosphate; (3) have desirable mouthfeel; and (4) do not have undesired flavor effects.